Process for the two-stage reaction of olefins with intermediate distillation

Abstract

A process reacts olefins having 4 to 20 carbon atoms and the feed stream used, containing at least linear olefins and branched olefins, is distilled between two reaction steps and only the high-boiler phase obtained in this distillation is subjected to the second reaction, a heterogeneously catalysed hydroformylation, a homogeneously catalysed hydroformylation or a homogeneously catalysed alkoxycarbonylation.

1 . A process for reacting olefins having 4 to 20 carbon atoms, comprising:
 a) providing a feed stream comprising at least linear olefins and branched olefins each having a same number of carbon atoms;   b) supplying the feed stream from a) to a reaction unit comprising one or more reactors, and carrying out a reaction in the reaction unit to obtain a product mixture, where the reaction is either a heterogeneously catalysed hydroformyiation in presence of synthesis gas, a homogeneously catalysed hydroformyiation in presence of synthesis gas or a homogeneously catalysed alkoxycarbonylation in presence of carbon monoxide and a C1 to C6 alcohol,   c) removing a residual stream from the product mixture from b), where the residual stream comprises at least unreacted olefins, from the reaction mixture;   d) distilling the residual stream from c) in at least one distillation column to obtain at least one low-boiler phase and one high-boiler phase, where 1% by weight to less than 50% by weight of the distilled feed stream is obtained as at least one low-boiler phase and where a proportion of linear olefins in the at least one low-boiler phase is less than a proportion of the linear olefins in the high-boiler phase; and   e) supplying the high-boiler phase from d) to a reaction unit comprising one or more reactors, and carrying out a reaction in the reaction unit, where the reaction is either a heterogeneously catalysed hydroformyiation in presence of synthesis gas, a homogeneously catalysed hydroformyiation in presence of synthesis gas or a homogeneously catalysed alkoxycarbonylation in presence of carbon monoxide and a C1 to C6 alcohol.   
     
     
         2 . The process according to  claim 1 , further comprising:
 reacting olefins having 7 to 16 carbon atoms in the process.   
     
     
         3 . The process according to  claim 1 , wherein a homogeneous catalyst system in the heterogeneously catalysed hydroformyiation comprises Co or Rh. 
     
     
         4 . The process according to  claim 1 , wherein a homogeneous catalyst system in the heterogeneously catalysed alkoxycarbonylation comprises a metal from group 8 to 10 of the Periodic Table of the Elements (PTE) or a compound thereof, a phosphorus-containing ligand and an acid as cocatalyst. 
     
     
         5 . The process according to  claim 1 , further comprising:
 subjecting the at least one low-boiler phase obtained in d) to a hydrogenation.   
     
     
         6 . The process according to  claim 5 , further comprising:
 carrying out the hydrogenation at a temperature of 100° C. to 180° C.   
     
     
         7 . The process according to  claim 5 , further comprising:
 using hydrogen in stoichiometric excess in the hydrogenation.   
     
     
         8 . The process according to  claim 5 , further comprising:
 using a supported catalyst comprising at least one transition metal from the group consisting of palladium, platinum, rhodium, ruthenium, nickel or mixtures thereof and a supporting material from the group consisting of aluminium oxide, silicon dioxide, titanium dioxide, magnesium oxide and mixtures thereof in the hydrogenation.   
     
     
         9 . The process according to  claim 1 , further comprising:
 carrying out the distillation in d) at an overhead temperature in a range from 40° C. to 100° C.   
     
     
         10 . The process according to  claim 1 , wherein a pressure at a top in the at least one distillation column in d) is 50 to 400 mbar. 
     
     
         11 . The process according to  claim 1 , wherein the at least one distillation column in d) comprises 10 to 100 trays. 
     
     
         12 . The process according to  claim 1 , further comprising:
 obtaining 5% by weight to 40% by weight of the distilled feed stream as at least one low-boiler phase in d).   
     
     
         13 . The process according to  claim 1 , further comprising:
 removing of the residual stream in c) by thermal separation.   
     
     
         14 . The process according to  claim 1 , wherein a conversion in the reaction in b) is at most 95%.